Finding 6v GC2 batteries at Costco?

[cookinwitdiesel]

When using multiple 6v batteries (combination of series and paralell to make a large 12v bank) do you have midpoint voltage monitoring?

I bought a Victron BMV-712 (kind of compulsively, not installing it yet) and want to learn more about how to properly monitor/protect the batteries.

[Thomasbeau]

Just wondering, do you need to replace the convertor to charge the two 6 volts versus the single 12 volt? Not sure if the convertor has a separate number but the panel in my Hideout is a WFCO WF-8930/50.

Thanks

[MarkEHansen]

When you set up the two 6v batteries, you wire them in series so they appear to the rest of the circuit (and the converter) as a 12v battery - so no, you don't need to change the converter.

[Thomasbeau]

I'm familiar with the wiring of the batteries. I wasn't sure if the composition of the batteries differed and that would require a convertor change. Such as using a lithium battery versus a standard battery.

[JRTJH]

[QUOTE=Thomasbeau;347719]I'm familiar with the wiring of the batteries. I wasn't sure if the composition of the batteries differed and that would require a convertor change. Such as using a lithium battery versus a standard battery.[/QUOTE]

Nope. The GC2 is a "flooded cell, lead/acid battery" (just a plain old "been around for ages" technology)

[busterbrown]

Originally Posted by Thomasbeau

Just wondering, do you need to replace the convertor to charge the two 6 volts versus the single 12 volt? Not sure if the convertor has a separate number but the panel in my Hideout is a WFCO WF-8930/50.

Thanks

That WFCO part number is for the power distribution panel, not for the OEM converter.

Going from a single 12 volt marine/RV battery (like a group 24) to dual 6 volt deep cycle batteries wired in series (like GC2) will more than triple the "usable" amp hours. With that said, the OEM converter may have a difficult time keeping the much larger battery bank topped off. I found this out first hand on a trip out west several months ago. I went from 64 amp hours in the single Interstate battery to 215 amp hours in dual GC2 Duracell's from Sams Club. When attempting to recharge the bank (from about 50%) via the converter (while plugged into our inverter generator), it would take nearly the entire day (about 8 hours) to get to a barely 80% charged state. The Interstate could bulk charge and get to an absorption state in just a few hours.

By the end of this camping season, I will have replaced the OEM converter with a more efficient 4 stage smart converter.

Here's a video that I found useful:

https://www.youtube.com/watch?v=mDEeSHrTv1k

[cookinwitdiesel]

I saw an interesting video today comparing the different battery types and their extended and lifetime costs. Pretty much, if you can stomachs the up front cost, lithiums were hands down far and away cheaper and better in just about every metric possible. It was very interesting.

https://youtu.be/URz1P82oHSU

http://www.imnotlostimrving.com/battery-info/

[busterbrown]

Originally Posted by cookinwitdiesel

I saw an interesting video today comparing the different battery types and their extended and lifetime costs. Pretty much, if you can stomachs the up front cost, lithiums were hands down far and away cheaper and better in just about every metric possible. It was very interesting.

https://youtu.be/URz1P82oHSU

http://www.imnotlostimrving.com/battery-info/

Hands down, the qualities of a LiFEPO4 battery bank supercede AGM and Lead-acid storage by a light year. Unfortunately, pricing is still making it difficult for 'generalized' acceptance.

Since a 180 "usable" amp hr lithium battery bank (90% of 200 amp hours) will cost up to $2000 vs an equivalent lead acid bank of 200 "usable" amp hrs (50% of 430) at a cost of $400, the average RV'er won't be inclined to make the switch anytime soon.

A well-maintained AGM or Lead-acid battery will still be the "go to" DC power source for the near future, or until lithium prices tumble. AGM and Lead-acid just have the financial advantage.

[cookinwitdiesel]

But they only have the upfront advantage, all after purchase costs (which are just as real but less obvious) strongly favor the lithiums. AND they weigh much less.

[busterbrown]

Originally Posted by cookinwitdiesel

But they only have the upfront advantage, all after purchase costs (which are just as real but less obvious) strongly favor the lithiums. AND they weigh much less.

Agreed that lithiums functionally are superior in almost every way, except when charge cycles take place below 32 degrees. In that regards, Lead-acid/AGM has the advantage.

But purchase price is undeniably the biggest hurdle for lithium. Like I mentioned before, if a lead acid battery can make it 5-6 years unscathed in an RV application for nearly 1/5 the cost of its lithium counterpart, outside of "keeping up with the Joneses", why would the general consumer need to transition to the new tech at these absurd prices?

[cookinwitdiesel]

Lower weight, better charge density, faster recharge, maintenance free, no explosion risk from off gassing, more durable and longer lasting

Just to name a few reasons. As I have learned more on it, I have pretty much made up my mind. Especially since my wife has mandated I just bought a ten year trailer - the investment will not go unused.

[sonofcy]

Originally Posted by busterbrown

Agreed that lithiums functionally are superior in almost every way, except when charge cycles take place below 32 degrees. In that regards, Lead-acid/AGM has the advantage.

But purchase price is undeniably the biggest hurdle for lithium. Like I mentioned before, if a lead acid battery can make it 5-6 years unscathed in an RV application for nearly 1/5 the cost of its lithium counterpart, outside of "keeping up with the Joneses", why would the general consumer need to transition to the new tech at these absurd prices?

Lithium at the low 3,000 cycles is the same lifetime cost as FLA, they are 60% of the cost of FLA at the more typical 5,000 cycles.
When you speak of FLA batteries lasting 5 to 6 years then you are talking extremely light usage. Per the manufacturers own specs FLA have a 1,000 cycle life span. For folks using their batteries a normal amount that equates to about 3 years. Where we are getting some pushback is that the issue is lifetime cost for full timers but for part timers who will never wear out there FLA in 6 years let alone 3 years the concept of a lithium battery lasting at least 18 years and likely 30 years is beyond their horizon.

[Thomasbeau]

Thank you Busterbrown, this was the answer I was looking for. I knew the panel and convertor were separate in my 5'ver but since the convertor is buried behind a wall I just tossed up the panel number. I thought maybe panels and convertors were often paired together in common configurations. Now I know that if I make the switch a changing of the convertor is something I should consider.

Thank you.

[MarkEHansen]

BusterBrown - The video you posted implies that trailers today come with a single-stage converter, but that's not correct, is it? I think that's a little misleading. I guess I'll have to dig into mine and find out what it is...

Even if they come with multi-stage converters, I understand there are better ones out there and so folks can still improve things.

[JRTJH]

Originally Posted by MarkEHansen

BusterBrown - The video you posted implies that trailers today come with a single-stage converter, but that's not correct, is it? I think that's a little misleading. I guess I'll have to dig into mine and find out what it is...

Even if they come with multi-stage converters, I understand there are better ones out there and so folks can still improve things.

Your trailer likely has a WFCO 8900 series (30 amp shore power) or a 9500 series (50 amp shore power) electrical power center. WFCO sells each of those "power center series" with different converter/charger installations.

As an example, the 8935 is a 30 amp system with a 35 amp converter/charger and the 8965 is a 30 amp system with a 65 amp converter/charger.

It's the same with the 9500 power center series. The 9540 is a 50 amp system with a 40 amp converter/charger and the 9580 is a 50 amp system with a 80 amp converter/charger.

Essentially, there are two basic power centers (one has a 30 amp shore power cord and the other has a 50 amp shore power cord). They all share a variety of converter/chargers, from a "light duty 35 amp DC system" to a "much heavier duty 80 amp DC converter/charger system"...

That said, chances are you have a WFCO 9560 (if your trailer is a 50 amp trailer) or a WFCO 8955 (if your trailer is a 30 amp trailer).

ALL of the WFCO power centers have interchangeable converter/chargers, so you can upgrade a 8935 power center to a 8965 power center by changing the converter/charger. That will increase your "battery charge capability from a maximum of 35 amps to 65 amps (just by changing the converter/charger.

To my knowledge, WFCO has not used a "single stage converter/charger since about 1998 or 1999.

Currently, ALL (every) WFCO converter/charger manufactured for RV power centers is a 3 stage converter/charger.

As for "better converter/chargers" being "out there". There are some competitive converter/chargers on the market. There you'll get into the same kind of question: Which is better, Ford, GM or RAM type of argument.....

[sonofcy]

Originally Posted by MarkEHansen

BusterBrown - The video you posted implies that trailers today come with a single-stage converter, but that's not correct, is it? I think that's a little misleading. I guess I'll have to dig into mine and find out what it is...

Even if they come with multi-stage converters, I understand there are better ones out there and so folks can still improve things.

Most if not all RV converter's are 3 stage, BUT they are not programmable and they are set to too low a voltage. They do this in order to make sure they do not overcharge since that condition is not only more noticeable than undercharge but slightly dangerous. Somebody asked Trojan what the number one reason for battery returns was and it was something like 90% undercharging. The other important difference between what they put in an RV and what 'real' chargers have is temperature compensation. You can google that if it's unfamiliar to you as to why it's important. The difference between what you can program and what comes with your RV looks like 14.6V and 14.4V. Doesn't seem like much but it is, and there are other programmable settings missing that make a difference. I don't remember the math or where I saw an understandable example but it might be Handy Bob and that is a long read. Keep in mind that the average weekender and 2 weeks vacation goer can get by with the wrong pre-installed battery and converter for years if they baby the batteries. Only if you are full time or even 6 months a year and especially with a residential refrigerator is getting the right batteries and charger critical. We swapped two 12v 75ah dealer batteries for 2 6V 225ah Trojan T105's (what most knowledgeable RVers use) Our fridge uses 1.5Kwh's per day so the two Trojans are good for 24 hrs when boondocking and is why we were going to install 2 more before we decided to put in 600AH of lithium and 8 or more solar panels etc.

[sonofcy]

Originally Posted by JRTJH

Your trailer likely has a WFCO 8900 series (30 amp shore power) or a 9500 series (50 amp shore power) electrical power center. WFCO sells each of those "power center series" with different converter/charger installations.

As an example, the 8935 is a 30 amp system with a 35 amp converter/charger and the 8965 is a 30 amp system with a 65 amp converter/charger.

It's the same with the 9500 power center series. The 9540 is a 50 amp system with a 40 amp converter/charger and the 9580 is a 50 amp system with a 80 amp converter/charger.

Essentially, there are two basic power centers (one has a 30 amp shore power cord and the other has a 50 amp shore power cord). They all share a variety of converter/chargers, from a "light duty 35 amp DC system" to a "much heavier duty 80 amp DC converter/charger system"...

That said, chances are you have a WFCO 9560 (if your trailer is a 50 amp trailer) or a WFCO 8955 (if your trailer is a 30 amp trailer).

ALL of the WFCO power centers have interchangeable converter/chargers, so you can upgrade a 8935 power center to a 8965 power center by changing the converter/charger. That will increase your "battery charge capability from a maximum of 35 amps to 65 amps (just by changing the converter/charger.

To my knowledge, WFCO has not used a "single stage converter/charger since about 1998 or 1999.

Currently, ALL (every) WFCO converter/charger manufactured for RV power centers is a 3 stage converter/charger.

As for "better converter/chargers" being "out there". There are some competitive converter/chargers on the market. There you'll get into the same kind of question: Which is better, Ford, GM or RAM type of argument.....

Better would be programmable with temperature compensation, that's not a Ford, RAM, GM thing, it's more like a 1920's Ford vs 2020's Ford thing.

[cookinwitdiesel]

What lithiums did you go with?

[sonofcy]

Originally Posted by Thomasbeau

Thank you Busterbrown, this was the answer I was looking for. I knew the panel and convertor were separate in my 5'ver but since the convertor is buried behind a wall I just tossed up the panel number. I thought maybe panels and convertors were often paired together in common configurations. Now I know that if I make the switch a changing of the convertor is something I should consider.

Thank you.

If you do want to install a better charger, what you will be doing is just disconnect the existing converter and adding a decent charger. That being said when I was thinking of doing that I never did find just a charger that was programmable with temperature compensation as a stand-alone unit. I only found inverters with that charger built in. Those will run close to $2,000 IIRC for a 2,000 watt and $3,000 for 3,000 watts. IF you are NOT a full timer you probably should just leave well enough alone and if you do boondock a little upgrade to 2 or 4 Trojan T105's depending on how long you want to be off grid. Of course your first purchase should be a Bogart Trimetric TM-2030-RV battery monitor so you know exactly what is happening to your battery. Check out some wiring diagrams and you will probably quickly decide on the need for a couple of bus bars for the + and - leads. Use marine grade, Blue Sea is good but they are appropriately priced. Study and use the Trimetric and you will be battery knowledgeable.

[travelin texans]

[QUOTE=sonofcy;347866]Better would be programmable with temperature compensation, that's not a Ford, RAM, GM thing, it's more like a 1920's Ford vs 2020's Ford

That would be just one more thing that most folks would never figure out & there'd be 100s of post on here of "how to I program my convertor?". The 3 stage that if plugged into shore power does it's thing on the last 3-4 rvs I've had & I didn't have even have to think about it. Simple is best!
Look how many posts just in the past couple months concerning the In Command system. Great idea to try & attract the millennials with high tech gadgets, but that's not the ones buying the majority of the rvs.
As for lithium batteries, I got just shy of 6 years fulltiming from the pair of no name batteries the dealer installed, no way would I, even if money was no object, be spending $300-400 each for lithium.